Luxury and debauchery still ruled in World War Two – if you were part of the wealthy elite portrayed in new series The Halcyon

Their antics have inspired ITV’s glossy new period drama The Halcyon, starring Steven Mackintosh, Olivia Williams and Kara Tointon.

With lavish costumes and blue-blooded scandal, it has been hailed the new Downton Abbey. And like Downton, it is produced by Chris Croucher, who told The Sun: “These hotels were London’s most glamorous air-raid shelters.

“Although rationing was around, Winston Churchill had a waiver for hotels and some top restaurants because he wanted still to be able to dine well.”

The show, starring Kara Tointon, is tipped as the successor to Downton Abbey

Even during the Blitz — which lasted from September 1940 to May 1941 — five-star palaces including the Ritz, Savoy and The Dorchester kept the party going with fine wines, caviar and lobster for anyone who could afford to indulge.

With the threat of “no tomorrow” as Britain suffered nightly raids, many lived for today and love affairs were fast, furious and frequent.

An air-vent behind The Dorchester was nicknamed “the hotplate” because it kept the local prostitutes warm. And the basement bar at the Ritz was dubbed “the Pink Sink” when it became popular for homosexual liaisons.

Churchill, centre, made sure certain hotels had rationing lifted so he could continue to live well

The guests were in the hotels as much for their safety as the champagne and oysters.

The Dorchester advertised that its impenetrable shell consisted of a core of thick metal cables deeply embedded into rafts of reinforced concrete. The Ritz bragged how its golden gilded walls concealed steel girders worthy of an American skyscraper.

Not to be outdone, the Savoy declared its air-raid shelters “the smartest in London”.

While the hotels suffered some bomb damage, all three avoided direct hits and remained open.

On Park Lane, the Grosvenor House Hotel’s walls were so thick that diners could not hear air-raid sirens. When raids were over, the house band would sing “All Clear! All Clear!” to the tune of whichever song they were playing at the time.

Over at the Savoy, the glass in the hotel’s revolving doors was painted dark blue as a concession to blackout rules.

During one night of vicious shelling, Communist protesters persuaded the Savoy to open its bomb shelter to the general public

The upper classes did not just flock to London’s best hotels for safety, sex and cocktails.

Many of their personal staff had been enlisted, leaving them to fend for themselves.

Exiled royals were familiar faces. The Albanian King Zog and Queen Geraldine took an entire floor of the Ritz and were rumoured to have paid their bills in bullion taken from their country’s gold reserves.

Claridge’s, in Mayfair, was a particular favourite for stateless European monarchs because it cut its rates, reflecting its slightly more vulnerable construction compared to its three rivals.

King George of Greece assumed the identity of “Mr Brown” when he checked in but fooled no one.

Queen Wilhelmina arrived from the Netherlands on a British destroyer. Her young son-in-law, Prince Bernhard, once shot out a bright light in a nearby penthouse for flouting the blackout rules.

For one night only in 1945, Churchill decreed Claridge’s suite 212 become Yugoslav territory to allow its pregnant queen to give birth to Crown Prince Alexander in her homeland. However, the young prince only held his royal title for the first few months of his life, until his father was deposed by communist authorities.

Dance and burlesque acts would have been regular features in the cabaret shows

Spies also flooded the hotels. Cambridge Five spy ring member Guy Burgess installed two agents at The Dorchester to watch ten targets each.

A suspected double Nazi agent, Stella Lonsdale, who was staying in room 591 of the Waldorf Hotel in West London, was interrogated at length by MI5. Rather than refusing to talk, she purred out a stream of sexual filth to the agents, leading one to describe her as “a woman whose loose living would make her an object of shame on any farmyard”.

He explained: “A hotel is very transient so there are potentially lots of mysterious international guests that Garland has to be very aware of. The hotel manager had a patriotic duty to have his eye on everyone.”

SEEING THE SIGNS

GOGGLEBOX STAR CHARGED

Political figures also loomed large. Part of the reason Churchill made the rationing exemption was so he could meet leaders in their rooms over a bottle of his beloved Pol Roger champagne.

In the Ritz’s Marie Antoinette suite, history was frequently written as Churchill, France’s Charles de Gaulle and future US president Gen Dwight Eisenhower plotted the Allies’ next move.

Eisenhower also had a concrete barrier installed at the front of The Dorchester for his protection.

British foreign secretary Edward Halifax slept beside his wife and mistress in the underground Turkish baths there — he did not realise the chamber projected out from the main hotel and was therefore one of the most vulnerable spots in the building.

Viewers can see some of these stories brought to life in The Halcyon, which starts on January 2, at 9pm on ITV.

She had a non-speaking role in the first scene of the show – in which Kara Tointon performs in a backless pink dresss

Cosy period dramas make for perfect winter viewing but are often filmed in summer. My day of minor stardom took place in July – on one of the hottest days of the year.

Wardrobe, hair and make-up takes two hours. I’d already sent my measurements and, when I arrived, was handed a beautiful satin gown with a velvet cowl neck.

Teamed with opera gloves and strappy black stilettos, I begin to look the part.

The set is staggering.

It may be in a West London warehouse but a full-scale hotel has been built, with a vast marble lobby, staircase and suites. Just past the lobby is the 1920s-style bar. My scene is set during a party for the hotel’s 50th anniversary, moments before an air-raid siren sounds. All the cast are on set, with around 50 extras.

The costuming, hair, and make-up were fantastic – I did feel I looked the part

All I have to do is cross behind series star Steven Mackintosh, place a glass on the bar and walk to the lobby. Now the temperature is nearing 40C, it’s the end of a long shoot and this is the final scene of the day.

“Action!” I begin to glide behind Steven but there is a crash. My glass has fallen over, ruining the scene. I’ve never been more embarrassed.

Armed with a new glass, it’s time for take two . . . which I nail. Hollywood won’t be calling any time soon, but I’m in what will be a huge hit for ITV.